1 files changed, 1 insertions, 0 deletions
diff --git a/gc.c b/gc.c
index 3c55fc6206..d976a90aac 100644
--- a/gc.c
+++ b/gc.c
@@ -15,6 +15,7 @@
 #include "ruby/st.h"
 #include "ruby/re.h"
 #include "ruby/io.h"
+#include "ruby/thread.h"
 #include "ruby/util.h"
 #include "eval_intern.h"
 #include "vm_core.h"